U.S. patent number 6,659,978 [Application Number 09/675,229] was granted by the patent office on 2003-12-09 for portable dosing apparatus.
This patent grant is currently assigned to Seiko Instruments Inc.. Invention is credited to Akihiro Iino, Masao Kasuga, Takayuki Kosaka, Takashi Yamanaka.
United States Patent |
6,659,978 |
Kasuga , et al. |
December 9, 2003 |
Portable dosing apparatus
Abstract
A low cost portable dosing apparatus enables the dispensing rate
to be changed while enabling solution to be continuously dispensed
to the body. The solution to be dispensed into the body is stored
in a tank unit. A pump unit pumps the solution from the tank unit
into the body of the patient. A controller controls pump unit
operation. The tank unit, pump unit, and controller are attached to
a wrist strap so that they can be easily connected and disconnected
from each other. A compact, thin ultrasonic motor with high output
per unit size drives the pump unit. A smaller pump unit is thus
available, improving the portability of the apparatus. The
ultrasonic motor is also substantially free of misoperation
resulting from exposure to magnetic fields because the ultrasonic
motor is not magnetically driven. Reliability is therefore
improved.
Inventors: |
Kasuga; Masao (Chiba,
JP), Kosaka; Takayuki (Chiba, JP), Iino;
Akihiro (Chiba, JP), Yamanaka; Takashi (Chiba,
JP) |
Assignee: |
Seiko Instruments Inc. (Chiba,
JP)
|
Family
ID: |
29713590 |
Appl.
No.: |
09/675,229 |
Filed: |
September 29, 2000 |
Foreign Application Priority Data
|
|
|
|
|
Oct 4, 1999 [JP] |
|
|
11-283448 |
Oct 15, 1999 [JP] |
|
|
11-294228 |
|
Current U.S.
Class: |
604/151; 604/67;
604/890.1 |
Current CPC
Class: |
A61M
5/14244 (20130101); A61M 5/14232 (20130101); A61M
5/152 (20130101); A61M 2005/14252 (20130101) |
Current International
Class: |
A61M
5/142 (20060101); A61M 5/145 (20060101); A61M
5/152 (20060101); A61M 001/00 () |
Field of
Search: |
;604/65-67,132,151,248,890.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Huson; Gregory L.
Assistant Examiner: deVore; Peter
Attorney, Agent or Firm: Adams & Wilks
Claims
What is claimed is:
1. A portable solution delivery apparatus for supplying a body with
a solution at a dispensing rate that can be varied, comprising: a
tank unit for holding the solution; a pump unit for pumping the
solution from the tank unit to the body; a controller for
controlling the pump unit; and a housing in which the tank unit,
the pumping unit, and the controller are removably disposed, the
housing being removably mountable to the body.
2. A portable solution delivery apparatus according to claim 1;
further comprising operation detection means for detecting pump
unit operation and outputting a detection signal to the
controller.
3. A portable solution delivery apparatus according to claim 1;
wherein the controller comprises dispensing parameter input means
for externally inputting a dispensing parameter; and a display for
displaying a dispensing parameter; and wherein the controller
controls the pump unit according to the input dispensing
parameter.
4. A portable solution delivery apparatus according to claim 1;
further comprising status information input means for inputting
status information indicative of a condition of the body; wherein
the controller controls the pump unit according to status
information from the status information input means.
5. A portable solution delivery apparatus according to claim 1;
wherein the tank unit comprises a solution tank that is expandable
for internally storing the solution; and pressure applying means
for applying pressure to the solution tank so as to reduce an
internal volume of the solution tank so as to pressurize the
solution.
6. A portable solution delivery apparatus according to claim 1;
wherein the pump unit comprises an actuator driven according to a
drive signal from the controller; a drive power transfer mechanism
for transferring drive power from the actuator; and a pump for
pumping solution by means of drive power transferred from the drive
power transfer mechanism.
7. A portable solution delivery apparatus according to claim 6;
wherein the actuator is an ultrasonic motor.
8. A portable solution delivery apparatus according to claim 6;
wherein the actuator is a piezoelectric actuator.
9. A portable solution delivery apparatus according to claim 6;
wherein the pump unit further comprises a ratchet mechanism
connected to one of the drive power transfer mechanism and the pump
for preventing backflow of the drive power.
10. A portable solution delivery apparatus according to claim 1;
wherein the pump unit comprises an actuator driven according to a
drive signal from the controller; and a pump for pumping solution
by means of drive power transferred from the actuator.
11. A portable solution delivery apparatus according to claim 10;
wherein the actuator is an ultrasonic motor.
12. A portable solution delivery apparatus according to claim 10;
wherein the actuator is a piezoelectric actuator.
13. A portable solution delivery apparatus according to claim 10;
wherein the pump unit further comprises a ratchet mechanism
connected to the pump for preventing backflow of the drive
power.
14. A portable solution delivery apparatus according to claim 1;
further comprising backflow prevention means for preventing the
pump unit from operating in reverse.
15. A portable solution delivery apparatus according to claim 1;
further comprising a needle disposed in a flow path of the solution
for injecting solution into the body.
16. A portable solution delivery apparatus for delivering a
solution to a body, comprising: a tank for holding the solution; a
storage compartment having a path therein through which the
solution is pumped; a piezoelectric actuator disposed in the
storage compartment for pumping the solution by changing the
capacity of the storage compartment by undergoing expanding and
contracting movement; and a controller for controlling the
piezoelectric actuator.
17. A portable solution delivery apparatus according to claim 16;
wherein the controller comprises dispensing parameter input means
for externally inputting a dispensing parameter; and a display for
displaying a dispensing parameter; and wherein the controller
controls the piezoelectric actuator according to the input
dispensing parameter.
18. A portable solution delivery apparatus according to claim 16;
further comprising status information input means for inputting
status information indicative of a condition of the body; wherein
the controller controls the piezoelectric actuator according to the
status information.
19. A portable solution deliver apparatus according to claim 16;
further comprising a needle provided in the flow path for injecting
the solution into the body.
20. A portable solution delivery apparatus for delivering a
solution to a body, comprising: a housing removably mountable to
the body; a tank disposed in the housing for holding the solution;
a pump unit disposed in the housing for pumping the solution from
the tank to the body; a controller removably disposed in the
housing for controlling the pump unit to deliver the solution at a
desired dispensing rate; and a delivery device for supplying the
solution to a desired part of the body; wherein the controller is
removable and replaceable by another controller to change the
dispensing rate of the solution.
21. A portable solution delivery apparatus according to claim 20;
wherein the controller comprises dispensing parameter input means
for externally inputting a dispensing parameter; and a display for
displaying a dispensing parameter; wherein the controller controls
the pump unit according to the input dispensing parameter.
22. A portable solution delivery apparatus according to claim 20;
further comprising status information input means for inputting
status information indicative of a condition of the body; wherein
the controller controls the pump unit according to status
information from the status information input means.
23. A portable solution delivery apparatus according to claim 20;
wherein the tank unit comprises a solution tank that is expandable
for internally storing the solution; and pressure applying means
for applying pressure to the solution tank to reduce an internal
volume of the solution tank so as to pressurize the solution.
24. A portable solution delivery apparatus according to claim 20;
wherein the pump unit comprises an actuator driven according to a
drive signal from the controller; a drive power transfer mechanism
for transferring drive power from the actuator; and a pump for
pumping solution by means of drive power transferred from the drive
power transfer mechanism.
25. A portable solution delivery apparatus according to claim 24;
wherein the actuator is an ultrasonic motor.
26. A portable solution delivery apparatus according to claim 24;
wherein the actuator is a piezoelectric actuator.
27. A portable solution delivery apparatus according to claim 20;
further comprising operation detection means for detecting pump
unit operation and outputting a detection signal to the
controller.
28. A portable solution delivery apparatus according to claim 20;
further comprising backflow prevention means for preventing the
pump unit from operating in reverse.
29. A portable solution delivery apparatus according to claim 20;
wherein the deliver device comprises a needle disposed in a flow
path of the solution for injecting the solution into the body.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a portable dosing apparatus that
is capable of continuously dispensing a solution and varying the
dispensing rate.
2. Description of Related Art
Portable drug dispensers that are worn by the patient and for
dosing the patient with a drug are needed so that the patient can
go about his or her normal daily activities while keeping his
symptoms under control. Portable drug dispensers of this type
include, for example, the compact peristaltic pump taught in
Japanese Patent Publication Laid-Open No. 280763/1990, and the
infusion pump taught in Japanese Patent Publication Laid-Open No.
236558/1987.
The peristaltic pump taught in Japanese Patent Publication
Laid-Open No. 280763/1990 has a first module that is a pump module
containing the injectable solution, and a second module that is a
motor module containing both a controller and motor. Both the first
and second modules can be installed and removed.
The infusion pump taught in Japanese Patent Publication Laid-Open
No. 236558/1987 is an integrated unit, but the speed of the motor
that is the source of pump drive power can be set manually, and the
dispensing rate is therefore adjustable.
Problem to be Solved
The operating cost of this type of portable dosing apparatus should
be low because it is used daily by the patient. It is also
necessary to be able to adjust the dosing rate according to the
patient's symptoms.
The dosing rate of the above-noted peristaltic pump, however, is
determined by the motor module, and the motor module must therefore
be replaced to change the dispensing rate. However, because the
motor module is part of the solution delivery path, replacing the
motor module to adjust the dispensing rate means that dosing stops
temporarily. Plural motor modules must therefore be provided if the
dispensing rate is to be adjustable, and the cost therefore
rises.
While the dispensing rate is adjustable with the above-noted
infusion pump, integration of all components into a single unit
means that the entire unit must be replaced when the solution runs
out. Dosing is therefore interrupted for a relatively long period
of time, and operating cost is high.
Both of the prior art devices described above are also powered by a
motor using magnetic flux as the drive power source, thus making
the power unit larger and reducing device portability. What's more,
the magnetic field generated by magnetic resonance imaging (MRI)
and other magnetic medical devices could cause the power unit to be
misoperated.
An object of the present invention is therefore to provide a low
cost portable dosing apparatus with an adjustable dispensing rate
that is capable of continuous dispensing even while changing the
dispensing rate.
A further object of the present invention is to provide a portable
dosing apparatus that uses a motor that does not use magnetic flux,
as the drive power source, and thereby achieves greater compactness
and increased reliability.
SUMMARY OF THE INVENTION
To achieve the above objects, a portable dosing apparatus (1) for
continuously dosing a body with a solution at a dispensing rate
that can be varied comprises, according to the present invention, a
tank unit (2) for holding the solution, a pump unit (3) for pumping
the solution from the tank unit to the body, and a controller (4)
for controlling the pump unit, configured such that the tank unit,
pump unit, and controller each being freely connectable and
disconnectable.
Thus comprised, the dispensing rate can be changed simply by
changing the controller. In other words, because it is not
necessary to replace any part of the solution dispensing path in
order to change the dispensing rate, the time during which
dispensing is interrupted when changing the dispensing rate is
extremely short.
Furthermore, it is only necessary to replace the tank unit when the
solution runs out. In addition, the relatively high cost but same
pump unit is used for a specific period of time. Operating cost is
therefore low.
It will also be noted that the portable dosing apparatus of our
invention is not limited to use with humans, but can also be used
with animals.
Furthermore, by further providing a means for securing the portable
dosing apparatus to the body, such as wrist strap 11, the portable
dosing apparatus can be easily attached to the body. Such an
exemplary means is a strap like that of a wristwatch.
The controller typically comprises a CPU, a reference signal
generating circuit for CPU operation, and a ROM for storing a
control program. The controller in our invention, however,
additionally has a dispensing parameter input means (such as
buttons 41b) for externally inputting dispensing parameters, and a
display (44) for displaying dispensing parameters so that the
controller can control the pump unit according to the dispensing
parameters.
It is yet further possible to adjust the dosage, dispensing rate,
and other dispensing conditions while confirming the information on
a display. It is therefore possible to easily and reliably change
the dispensing parameters without replacing the controller.
Yet further preferably, the portable dosing apparatus also has a
status information input means (42) for inputting status
information indicative of a condition of the body. In this case the
controller controls the pump unit according to status information
from this status information input means.
If such patient information as the heart rate, blood pressure,
blood sugar, is entered, the controller can, using the control
program stored to ROM, for example, use the supplied information to
control the pump unit. As a result, dosage can be easily optimally
adjusted even if a person with specialist knowledge is not
present.
The tank unit of this portable dosing apparatus preferably has a
solution tank (21) that is expandable for internally storing the
solution; and a pressure applying means (23) for applying pressure
to the solution tank in a direction reducing an internal volume of
the solution tank so as to pressurize the solution.
The pressure applying means (23) can thus pressurize the solution
in the solution tank, enabling the solution to flow easily from the
solution tank. The load on the pump unit upon dispensing is
therefore low, and solution's backflow is suppressed.
The pump unit preferably has an actuator driven according to a
drive signal from the controller; a drive power transfer mechanism
(such as gear train 34) for transferring drive power from the
actuator; and a pump (33) for pumping solution by means of drive
power transferred from the drive power transfer mechanism.
This actuator is preferably an ultrasonic motor (5) or a
piezoelectric actuator.
By using a compact ultrasonic motor or piezoelectric actuator with
high output per unit volume as the drive source for the pump unit,
the size of the pump unit is reduced and the portability of the
portable dosing apparatus is improved.
Furthermore, because the ultrasonic motor and piezoelectric
actuator are not magnetically driven, there is substantially no
chance of misoperation when close to a magnetic device. The
reliability of the portable dosing apparatus is thus improved.
Further, the pump unit preferably comprises an actuator driven
according to a drive signal from the controller; and a pump (73)
for pumping solution rotatively by means of drive power transferred
directly from the actuator.
This actuator in this case is again preferably an ultrasonic motor
(8) or a piezoelectric actuator (63a).
By using a compact ultrasonic motor or piezoelectric actuator with
high output per unit volume as the drive source for the pump unit,
the size of the pump unit is reduced and the portability of the
portable dosing apparatus is improved.
Furthermore, because the ultrasonic motor and piezoelectric
actuator are not magnetically driven, there is substantially no
chance of misoperation when close to a magnetic device. The
reliability of the portable dosing apparatus is thus improved.
Furthermore, because the ultrasonic motor or piezoelectric actuator
directly drive the pump unit, a power transfer mechanism is not
needed, and a compact, lightweight pump unit can thus be
achieved.
Furthermore, the number of the parts is reduced, thus minimizing
the manufacturing cost.
The portable dosing apparatus further preferably comprises an
operation detection means (such as rotational distance detector 37)
for detecting pump unit operation and outputting a detection signal
to the controller.
The reliability of the portable dosing apparatus is yet further
improved as a result of the controller controlling the pump unit
while monitoring pump unit operation.
Yet further preferably, the portable dosing apparatus additionally
has a backflow prevention means (such as ratchet 33e) preventing
the pump unit from operating in reverse.
In this case the backflow prevention means significantly lowers the
chances that the pump will operate in reverse or the solution
backflow will occur. The reliability of the portable dosing
apparatus is thus yet further improved.
Yet further preferably, the portable dosing apparatus also has a
needle (12) for injecting solution to the body.
Other objects and attainments together with a fuller understanding
of the invention will become apparent and appreciated by referring
to the following description and claims taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a portable dosing apparatus according
to a first embodiment of the present invention;
FIG. 2 is a more detailed block diagram of the portable dosing
apparatus 1 shown in FIG. 1;
FIGS. 3 and 4 show how the portable dosing apparatus 1 is typically
worn by a user;
FIG. 5 is a side view of the tank unit 2 shown in FIG.
FIG. 6 is a top view of the pump unit 3 shown in FIG. 1;
FIG. 7 is a section view of an ultrasonic motor 5 that is the power
source for pump unit 3 in the first embodiment shown in FIG. 1;
FIG. 8 is a circuit diagram of the drive signal generating circuit
of ultrasonic motor 5 in the first embodiment shown in FIG. 1;
FIG. 9 is a circuit diagram of the drive state detection circuit
for detecting operation of pump unit 3 in the first embodiment
shown in FIG. 1;
FIG. 10 is a block diagram of the control unit 4 in the first
embodiment shown in FIG. 1;
FIG. 11A is a top view of an alternative version of pump unit 3,
and FIG. 11B is a section view of the same;
FIG. 12 is a block diagram of a portable dosing apparatus according
to a second preferred embodiment of the invention;
FIG. 13 is a section view of the pump 73 and ultrasonic motor 8 in
the second preferred embodiment of the invention shown in FIG. 12;
and
FIG. 14 is a plan view of the pump 73 and ultrasonic motor 8 in the
second preferred embodiment of the invention shown in FIG. 12.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
A first preferred embodiment of a portable dosing apparatus
according to the present invention is described below with
reference to the accompanying FIGS. 1 to 10.
FIG. 1 is a block diagram of this portable dosing apparatus 1
comprising a tank unit 2, pump unit 3, and control unit 4. FIG. 2
is a more detailed block diagram of the components shown in FIG.
1.
FIGS. 3 and 4 illustrate how the portable dosing apparatus 1 is
typically worn by a user.
FIG. 5 is a side view of the tank unit 2 shown in FIG. 1. FIG. 6 is
a top view of the pump unit 3. FIG. 7 is a section view showing
details of an ultrasonic motor 5 that is the power source for pump
unit 3. FIG. 8 is a circuit diagram of the drive signal generating
circuit 36a of ultrasonic motor 5, and FIG. 9 is a circuit diagram
of the drive state detection circuit 36b for detecting operation of
pump unit 3. FIG. 10 is a block diagram of the control unit 4.
Referring to FIG. 1, the tank unit 2 of the portable dosing
apparatus 1 internally holds the solution to be dispensed; the pump
unit 3 dispenses the solution from tank unit 2 to the patient; and
the control unit 4 controls the pump unit 3. As shown in FIGS. 2,
3, and 4, these units are attached to a wrist strap 11 so that they
can be connected and disconnected from each other.
As described more fully below, the control unit 4 controls pump
unit 3 to adjust the dispensing rate according to such patient
information as the blood pressure, heart rate, and blood sugar. The
control unit 4 also monitors pump unit 3 drive status.
As shown in FIG. 4, solution pumped by pump unit 3 is injected into
the patient's body by way of needle 12.
As shown in FIG. 2 and FIG. 5, tank unit 2 has a bellows-like
solution tank 21 disposed on a base 22, and a pressurizing
mechanism 23 whereby force can be applied so as to push down on
solution tank 21.
Solution outlet 21a for connecting solution tank 21 to the inlet 31
of pump unit 3, further described below, is disposed on the bottom
of solution tank 21 passing through base 22.
It should be noted that solution tank 21 shown in is FIG. 5
inflated by the solution stored therein. The solution in solution
tank 21 is thus pressurized by the force applied from pressurizing
mechanism 23 and the compressive force of the solution tank 21
itself.
As shown in FIG. 2 and FIG. 6, pump unit 3 has an inlet 31 through
which solution is introduced to the pump unit 3, an outlet 32 from
which solution leaves the pump unit 3, a pump 33 for pumping
solution introduced from inlet 31 out from outlet 32, an ultrasonic
motor 5 for driving pump 33 by means of intervening gear train 34,
ultrasonic motor power source 35, and ultrasonic motor drive
circuit 36.
As shown in FIG. 6, pump 33 has a flexible tube 33a connecting
inlet 31 and outlet 32 disposed along the inside wall of a hollow
circular container 33b. A disc 33c turned by drive power from
ultrasonic motor 5 is disposed coaxially to and inside circular
container 33b. Independently rotating rollers 33d are disposed at
120 degree intervals around the side of disc 33c so that the
rollers 33d press against flexible tube 33a.
Pump 33 is thus a pump that pushes solution inside flexible tube
33a from inlet 31 to outlet 32 as a result of rollers 33d pushing
against and rotating along the surface of flexible tube 33a.
To mechanically prevent disc 33c from rotating in the opposite
direction, a ratchet 33e (backflow prevention means) is also
disposed to disc 33c.
A rotational distance detector 37 (operation detection means) is
further disposed to one of the gears of gear train 34. This
rotational distance detector 37 has a plurality of holes 37a in the
gear spaced at a constant angular increment, a light emitting
means, and a photodiode 37b. This rotational distance detector 37
detects the distance of gear train 34, that is disc 33c, rotation,
and outputs a detection signal to control unit 4 by way of drive
circuit 36.
As shown in FIG. 7, ultrasonic motor 5 has a disc-shaped
piezoelectric element 51; disc-shaped vibrator 52 fixed to the top
of piezoelectric element 51; a plurality of protrusions 53 disposed
integrally to the top of vibrator 52; a spindle 54 passing through
the centers of piezoelectric element 51 and vibrator 52 and
supporting them on a base; a rotor 55 supported and rotating freely
on spindle 54; leaf spring 56 urging rotor 55 against protrusions
53; and lead 57 for transmitting a drive signal from drive circuit
36 to piezoelectric element 51.
It should be noted that rotor 55 has on top a gear 55a that meshes
with gear train 34. In addition, piezoelectric element 51 is
divided circumferentially into, for example, six parts, these parts
being alternately polarized oppositely and divided each in two
equal parts. The protrusions 53 are disposed at the border between
these polarized segments such that one protrusion 53 is located at
every other polarized segment.
This ultrasonic motor 5 converts electrical energy directly into
mechanical energy, features high output per unit volume, and is
resistant to effects from a magnetic field.
The drive circuit 36 comprises a drive signal generating circuit
36a as shown in FIG. 8, and a drive state detection circuit 36b as
shown in FIG. 9.
The drive signal generating circuit 36a is a common
self-oscillation circuit as generally used in ultrasonic motor
drive circuits. Tri-state buffer 36c for drive signal output is
controlled by control unit 4.
Drive state detection circuit 36b amplifies and outputs a signal
detected by photodiode 37b based on a signal generated by light
emitting means 37c, which may be an LED. Drive state detection
circuit 36b is turned on and off by control unit 4.
As shown in FIG. 2 and FIG. 10, control unit 4 has a CPU 41 for
directly controlling drive circuit 36; ROM 41a to which a control
program is prestored; dispensing parameter input means 41c such as
buttons 41b for inputting a user-generated signal to CPU 41;
reference signal generator 43 for generating a reference signal for
driving CPU 41; display 44 for displaying the dispensing rate,
dose, and biological information as controlled by CPU 41; and power
source 45.
A status information input means 42 can also be provided for
inputting to CPU 41 a signal indicative of the patient
condition.
As shown in FIG. 10, display 44 consists basically of an LCD panel
44a and LCD driver 44b. CPU 41 has a plurality of buttons 41b as
the dispensing parameter input means, including an on/off button,
dispensing rate adjusting button, and an interval adjustment
button.
Following the control program stored to ROM 41a, CPU 41 controls
ultrasonic motor 5 according to a signal input from buttons 41b and
status information input means 42 to adjust the dosage (volume) and
dispensing rate.
When the solution is consumed and must be replenished with the
portable dosing apparatus 1 described above, it is only necessary
to replace tank unit 2. Operating cost is therefore low.
Furthermore, the dosage and dispensing rate can be adjusted while
confirming the dispensing conditions on display 44. It is also
possible to replace only the control unit 4 to adjust the
dispensing conditions. As a result, it is not necessary to remove
or replace any part of the dispensing path in order to change the
dispensing conditions. Dispensing the solution is interrupted for
only a very short time when changing the dispensing rate.
The dosage can also be easily adjusted to be optimum even when a
person with specialized knowledge is not present because control
unit 4 can automatically adjust dispensing conditions according to
patient information detected and supplied from status information
input means 42.
Furthermore, the load on ultrasonic motor 5 is small because
pressurizing mechanism 23 and solution tank 21 both pressurize the
solution in solution tank 21, and the solution is thus able to flow
easily from the solution tank 21.
Yet further, by using a compact ultrasonic motor 5 featuring high
output per unit volume as the drive source for pump unit 3, the
size of the pump unit is reduced and the portability of the
portable dosing apparatus is thereby improved.
Yet further, because the ultrasonic motor 5 is not magnetically
driven there is substantially no possibility of misoperation when
close to a magnetic device, that is, when exposed to a magnetic
field. The reliability of the portable dosing apparatus 1 is
thereby further improved.
The control unit 4 can also control pump unit 3 while monitoring
the pump unit 3 operating status by means of rotational distance
detector 37 and drive state detection circuit 36b. Pump unit 3 is
also prevented by the ratchet 33e from operating in reverse,
thereby yet further improving the reliability of the portable
dosing apparatus 1.
Embodiment 2
The portable dosing apparatus 2 according to this second embodiment
of the invention uses the pump unit 7 shown in FIGS. 12 to 14 in
place of the pump unit 3 of the first embodiment. FIG. 12 is a
detailed block diagram of this portable dosing apparatus 122, FIG.
13 is a section view of the pump unit 7, and FIG. 14 is a plan view
of the pump unit 7.
It should be noted that like parts in this second embodiment and
the first embodiment described above are identified by like
reference numeral, and further description thereof is thus omitted
below.
Pump unit 3 and pump unit 7 differ in that whereas pump unit 3
comprises ultrasonic motor 5, outlet 32, inlet 31, gear train 34,
drive circuit 36, power source 35, and pump 33, and pump 33 is
driven by ultrasonic motor 5 by way of gear train 34, pump unit 7
does not have a gear train 34. The ultrasonic motor 8 used in pump
unit 7 in place of ultrasonic motor 5 directly drives pump 73,
which replaces pump 33.
This is described in further detail below.
As shown in FIG. 12, FIG. 13, and FIG. 14, pump unit 7 comprises
inlet 31 and outlet 32, pump 73 for pumping solution in from inlet
31 and out from outlet 32, ultrasonic motor 8 for directly driving
pump 73, power source 35 for ultrasonic motor 8, and ultrasonic
motor drive circuit 36.
As shown in FIG. 14, pump 73 has a flexible tube 33a connecting
inlet 31 and outlet 32 disposed along the inside wall of a hollow
circular container 133b. ultrasonic motor 8 is disposed in circular
container 133b so that the motor rotor 155 is concentric to
circular container 133b. Independently rotating rollers 33d are
disposed at 120 degree intervals around the side of rotor 155 so
that the rollers 33d press against flexible tube 33a. It should be
noted that rotor 155 and ultrasonic motor 8 are not contained in
pump 73, and are further described below.
Pump 73 is thus a pump that pushes solution inside flexible tube
33a from inlet 31 to outlet 32 as a result of rollers 33d pushing
against and rotating along the surface of flexible tube 33a.
A plurality of reflectors 137a are disposed at a constant angular
interval around rotor 155 on the side thereof opposite the surface
that contacts protrusions 53. The rotational distance detector 37
(operation detection means) comprising a light emitting means and
photodiode 37b is disposed above reflectors 137a with a specific
gap therebetween. The rotational distance detector 37 thus detects
the distance of rotor 155 rotation, and supplies a corresponding
detection signal to control unit 4 by way of drive circuit 36.
As shown in FIG. 13, the ultrasonic motor 8 has a disc-shaped
piezoelectric element 51; disc-shaped vibrator 52 fixed to the top
of piezoelectric element 51; a plurality of protrusions 53 disposed
integrally to the top of vibrator 52; a spindle 54 passing through
the centers of piezoelectric element 51 and vibrator 52 and
supporting them on a base; rotor 155 supported and rotating freely
on spindle 54; leaf spring 56 urging rotor 155 against protrusions
53; and lead 57 for transmitting a drive signal from drive circuit
36 to piezoelectric element 51. It will be remembered that rollers
33d are disposed to rotor 155 in this exemplary embodiment.
By thus disposing rollers 33d to rotor 155 and placing the flexible
tube 33a around the outside of rotor 155 so that it is squeezed
between rollers 33d and circular container 133b, pump 73 can be
driven directly by ultrasonic motor 8. By thus eliminating gear
train 34, pump unit 7 can be effectively downsized. Assembly is
also simplified, and manufacturing cost is reduced, because the
number of parts is also reduced.
It will also be obvious to one with ordinary skill in the related
art that the present invention shall not be limited to the above
described preferred embodiments and can be varied in many ways
without departing from the scope of the accompanying claims.
For example, a pump unit 6 shown in FIG. 11 can be used in place of
pump unit 3.
As shown in the plan view in FIG. 11A and the section view in FIG.
11B, pump unit 6 has inlet 61, outlet 62 and a storage compartment
63. Inlet 61 and outlet 62 open and close by means of a
piezoelectric actuator 61a, 62a, respectively. A storage
compartment 63 connected to inlet 61 and outlet 62 temporarily
stores solution. This pump unit 6 is driven by a piezoelectric
actuator driver 64.
A piezoelectric actuator 63a is also disposed to one side of
storage compartment 63. Piezoelectric actuator 63a can be driven to
expand or contract itself, thus to change and adjust the capacity
of storage compartment 63.
In other words, pump unit 6 operates by opening only inlet 61,
expanding storage compartment 63 to draw solution therein, then
closing inlet 61 and opening outlet 62, and then compressing
(contracting) storage compartment 63 to propel solution from outlet
62. The benefits described above can also be achieved with this
pump unit 6.
It should be noted that other than making the portable dosing
apparatus larger and more susceptible to the effects of magnetic
fields, a portable dosing apparatus according to our invention can
also be achieved using a motor that is driven using magnetic flux,
and the type of motor or actuator used with our invention is
therefore not specifically limited.
Furthermore, while a disc shaped ultrasonic motor is used in these
embodiments as the ultrasonic motor, the invention shall obviously
not be so limited. For example, the ultrasonic motor can use a
rectangular, annular, or other shape of vibrator. In addition, the
drive principle can use a standing wave or progressive wave. The
shape or operating principle of the ultrasonic motor shall
therefore not be specifically limited.
As described above, operating cost is low because it is only
necessary to replace the tank unit when the solution runs out.
It is also possible to replace only the pump unit to, for example,
change the type of solution, sterilize, or repair the pump
unit.
It is yet further possible to adjust the dosage, dispensing rate,
and other dispensing conditions while confirming the information on
a display and also by replacing only the controller. It is
therefore not necessary to change any parts of the solution
delivery path when changing the dispensing conditions.
The time that dispensing is interrupted when changing the
dispensing rate is therefore extremely short.
Furthermore, because the controller directly adjusts the dispensing
conditions according to patient (biological) information, dosage
can be easily optimally adjusted even if a person with specialized
knowledge is not present.
The load on the pump unit is also low because the solution in the
solution tank is pressurized by a pressure applying means and can
thus flow easily from the solution tank.
Furthermore, the size of the pump unit is reduced and the
portability of the portable dosing apparatus is improved if a
compact ultrasonic motor or piezoelectric actuator with high output
per unit volume is used as the drive source for the pump unit.
Furthermore, because the ultrasonic motor and piezoelectric
actuator are not magnetically driven, there is substantially no
chance of misoperation when close to a magnetic device. The
reliability of the portable dosing apparatus is thus improved.
Furthermore, because the ultrasonic motor or piezoelectric actuator
directly drive the pump unit, a power transfer mechanism is not
needed, and a compact, lightweight pump unit can thus be
achieved.
The number of parts is also reduced and manufacturing cost can
therefore be kept down.
The reliability of the portable dosing apparatus is yet further
improved as a result of the controller controlling the pump unit
while monitoring pump unit operation, and a backflow prevention
means significantly lowers the chances that the pump will operate
in reverse or the solution backflow will occur.
Although the present invention has been described in connection
with the preferred embodiments thereof with reference to the
accompanying drawings, it is to be noted that various changes and
modifications will be apparent to those skilled in the art. Such
changes and modifications are to be understood as included within
the scope of the present invention as defined by the appended
claims, unless they depart there from.
* * * * *